Isopods

Abstract

The order Isopoda is diverse (̃10,300 described species worldwide) and common in almost all environments --- marine, terrestrial, and freshwater. A total of 78 marine species have been reported from Costa Rica (46 species from the Caribbean coast and 34 from the Pacific), comprising 6 suborders and 24 families. Two species occur on both coasts: Excirolana braziliensis and Cirolana parva. Numerous additional species are expected to occur in Costa Rican waters, probably three times this number, but due to the paucity of research on this taxon in this region only these 78 can be included in our species lists. Only two broad surveys have been accomplished for Costa Rican isopods: Brusca & Iverson's (1985) survey of the Pacific coast, and an unpublished survey of the isopods of Cahuita (Brusca & White, in preparation). Representatives of at least eight families (Anthuridae, Ancinidae, Sphaeromatidae, Cirolanidae, Corallanidae, Aegidae, Gnathiidae, Holognathidae) occur on both the Pacific and Caribbean coasts. The most specious families of isopods on Costa Rican shores are: Asellota (16 species), Anthuridae (14 species), Sphaeromatidae (13 species), and Cirolanidae (seven species).